ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 101 



of external plates, Diplolepidacese for those in which the external 

 series is double ; this latter section will comprise all mosses with a 

 double peristome. 



The type of structure in the Orthotrichacese is very uniform ; six- 

 teen single or eight double teeth, flat and thin, with sometimes 

 prominent trabeculse on the outside, never on the inside, reflexed when 

 dry in many species, radiating in others ; the external layer is thicker 

 and ordinarily coloured, and is composed of two series of rectangular 

 plates, papillose, or less often striated ; the internal layer thin and 

 hyaline, plane and uniform, composed of a single series of rectangular 

 or square cells. 



This is also the normal structure of the peristome in the Splach- 

 nacese ; but certain species present curious specialities which are 

 described in detail, and which attain their greatest complexity in the 

 genus S'plachnum. Here the peristome retains till maturity certain 

 points of structure, which in other genera disappear in the course of 

 development ; otherwise the structure is that of Tayloria, Tetraplodon, 

 Dissodon, and the typical Orthoti'ichaceEe. 



Solmsiella, a new genus of Mosses.* — The following characters 

 are given by K. Miiller to a new genus of Musci obtained from Java 

 by Count Solms-Laubach : — Musci hypopterygiacei minuti depressi 

 prostrati jungermannioidei teneri chlorophyllosi viridissimi ; folia 

 tetrasticha caulem compressum sistentia, superiora majora oblongo- 

 orbicularia obtusa, inferiora minora magis ligulata et magis distantia 

 obtusata, omnia enervia, minute dense parenchymatice areolata ; 

 calyptra minuta cylindracea latere fissa dimidiata stylo terminata 

 tenera fugax ; theca in perichtetio folioso brevi laterali tenero erecta 

 ovalis leptoderma pallida gymnostoma exannulata breviter operculata 

 fabroniacea. Inflorescentia monoica. 



Spore-coats and Germination of Hepaticse.t — H. Leitgeb de- 

 scribes in detail the formation and structure of the spores of Sphcero- 

 carpus terrestris. They remain combined into tetrads inclosed in a 

 common membrane, the perinium, on the surface of which is a con- 

 nected network of delicate ridges. Each spore has a cuticularized 

 extine, also reticulated on its surface, and a smooth homogeneous 

 intine of cellulose. The mother-cells of the tetrads are inclosed in a 

 thick cell-v^all ; the innermost lamella of this is differentiated into a 

 dense layer, which becomes cuticularized and gradually less and less 

 capable of swelling, and forms the reticulated perinium ; the outer 

 portions of the envelope are capable of swelling strongly. While this 

 is proceeding, first the extine and then the intine of each spore is 

 developed. Ultimately the outermost portion of the envelope is con- 

 verted into mucilage, and the perinium assumes a deep brown colour. 



In Gorsinia marchantioides the structure of the spores is somewhat 

 more complicated, their membrane consisting of three sharply sepa- 

 rable layers, the outermost of which, the perinium, again consists of 



* Bot. Centralbl., xix. (1884) pp. 147-9. 



t Leitgeb, H., 'Ueber Bau u. Entwickelung der SporenliautQ u. tteren 

 Verhalten bei der Keimung,' 112 pp. (3 pis.) Graz, 1884. 



